Many types of heavy equipment utilize final drives, differentials and transmissions. In some cases, the only way to access the oil in the transmission and final drive is through a single oil port that is located on the equipment's wheel or track. Depending on the service action that is required, the oil port must be positioned differently. To fill the oil, the oil port must be located at the top of the wheel or track. To drain the oil, the oil port must be located at the bottom of the wheel. Oil sampling and level checking also require the oil port to be positioned differently in relation to the ground.
To position the oil port for each service action often requires two people. One person needs to drive the equipment so that the wheels and tracks rotate the oil port into the correct position and another person watches the oil port to signal to the driver that the oil port is in position. If only one person is available, the process is time consuming. The single person must get into the equipment to drive forward or backward and then the same person must get back out of the equipment to check the oil port. The process is repeated until the oil port is in the correct location.
Sensors have been used in the automotive arts for a number of purposes. The following are some examples. US 2007-285228 describes a retrofit sensor with wireless communication capability. The sensing unit is self-contained and may be mounted on a vehicle in different ways, including magnetism. The sensor can be used to monitor functional characteristics, faults and other conditions, and may be applied to oil and fluid ports on a vehicle. The sensor comprises a “speed sensing device”. However, the sensor does not provide information about the position of the oil port on a rotating wheel or track, nor can the sensing device correlate oil port position to the orientation of the sensing device.
KR 101038500 discloses a wireless sensing device for determining the state of a butterfly valve. The device comprises a sensing terminal on a rotating shaft and a sensor unit that measures the rotation angle of the rotating shaft by detecting the position of the sensing terminal.
U.S. Pat. No. 7,296,810 describes a method and apparatus for determining relative position of relatively movable members. The sensor includes a body mountable in a predetermined position to a first member, and a coupler being adjustably connectable to a second member and connectable in predetermined relation to an input of the sensor for coupling the input to the second member. The coupler is adjustably connectable to the second member in a predetermined relation to the first member such that when the input is connected to the coupler and the body is mounted in the predetermined position on the first member. The input and the body portion will be relatively positioned such that the sensor will provide a predetermined signal when the first and second members are in predetermined relative position. This document does not describe correlating oil port position to the orientation of a sensing device.
U.S. Pat. No. 5,223,822 describes a valve position indicator that has graphical information written on a drum that rotates with a valve actuator shaft. Rotation of the actuator shaft opens and closes the valve and the graphical information is correlated to the open or closed state of the valve, which depends on the rotational position of the actuator shaft. Sensors can also be used to determine the rotational position of the actuator shaft.
U.S. Pat. No. 6,978,196 describes a method of identifying a valve on a vehicle wheel. The method used an rf emitting tool to excite an identifier in a valve that then transmits data to a receiver connected to a computer.
U.S. Pat. No. 6,778,063 describes an angular position sensor for determining the angular position of a rotating shaft.
U.S. Pat. No. 5,711,245 describes a vehicle a method and apparatus for aligning a vehicle fluid output port with an external receptacle. The apparatus is based on an extendible flag that can be used as a reference.
There remains a need in the art for a simple, efficient method by which a single operator can determine the position of an oil port on a rotating element.